216745819 has 2 divisors, whose sum is σ = 216745820. Its totient is φ = 216745818.

The previous prime is 216745807. The next prime is 216745829. The reversal of 216745819 is 918547612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 216745819 - 2⁷ = 216745691 is a prime.

It is a super-2 number, since 2×216745819² = 93957500107961522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (216745829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108372909 + 108372910.

It is an arithmetic number, because the mean of its divisors is an integer number (108372910).

Almost surely, 2^216745819 is an apocalyptic number.

216745819 is a deficient number, since it is larger than the sum of its proper divisors (1).

216745819 is an equidigital number, since it uses as much as digits as its factorization.

216745819 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120960, while the sum is 43.

The square root of 216745819 is about 14722.2898694463. The cubic root of 216745819 is about 600.6897798505.

The spelling of 216745819 in words is "two hundred sixteen million, seven hundred forty-five thousand, eight hundred nineteen".